Setting carriage return mechanism

ABSTRACT

A device for the step-by-step motion of a setting carriage of a calculating machine operated in the course of a division operation. A first bell crank is mounted on a stationary shaft for rotation by a rod for operating the machine. The shaft loosely extends through an elongated slot in a second bell crank having one arm operably connected to a swingable arm of the first bell crank and connected by a tension spring to a machine frame and another arm swingable into engagement with one of stops on the carriage. The spring biases the second bell crank so that the latter, when actuated by said first bell crank, is first rotated about the stationary shaft until said another arm engages and depresses one of the stops and then is moved linearly to shift the carriage a step.

United States Patent Barozzi et a].

srz'muo CARRIAGE RETURN MECHANISM inventors: Gian Piero Banoul; Glancarlo l-loreschi, both of Crema, ltaly Assignee: Citizen Watch Co., Ltd.,- Tokyo,

Japan Filed: Jan. 11, 1971 Appl. No.: 105,275

Foreign Application Priority Data Feb. 11,1970 Italy ..20472-A/70 References Cited UNITED STATES PATENTS 9/1959 Gelling ..235/60 R 6/1960 Anderson ..'.235/60 TK 9/1962 Bacher ..235/60 TK 4/1963 Capellaro ..235/l45 X 51 3,703,986 1' Nov. 28, 1972 m ExamineF-Richard a. Wilkinson [57] ABSTRACT A device for the step-by-step motion of a setting carriage of a calculating machine operated in the course of a division operation. A first bell crank is mounted on a stationary shaft for rotation by a rod for operating the machine. The shaft loosely extends through an elongated slot in a second bell crank having one arm operably connected to a swingable arm of the first bell crank and connected by a .tension spring to a machine frame and another arm swingable into engagement with one of stops on the carriage. The spring biases the'second bell crank so that the latter, when actuated by 'said first bell crank, is first rotated about the stationary shaft until said another arm engages and depresses one of the stops and then is moved linearly to shift the carriage a step.

4 Clalns, 3 Drawing Figures PATENTEDnnvze m2 3, 703, 986

INVENTOR HiPMJAwM ATTORNEY 6.2 BAROZZI *aflonsscul I SETTING CARRIAGE RETURN MECHANISM The presentinvention relates to a device for backstepping a setting carriage of a calculating machine immediately after the clearing of stops in the row of zero stops in the course of a division operation.

As is well known, .a conventional calculating machine employs the means for stepping back the carriage, and the means for clearing the stops in the row of zero stops, which means are both used in the course of a division operation of the machine. These means usually consist of two sets of separate mechanisms which are automatically operated by a motor or a main shaft. For this reason, two separate driving systems are required for these two mechanisms. Axgreater number of components is therefore essentially .required, with resultant increase in the cost ofthe machine and in the possibility of machine trouble and error.

As already well known, furthermore, the carriage is shifted'step-by-step after the completion of the clearing of the zero stops (or vice-versa), i.e. the clearing of the stops must be performed before the stepping motion of the carriage (or vice-versa). In the case where two drives are employed in acalculating machine, thereis required an increased amount of working time which is equal to the sum of the periods of time taken by the operations of the two drives and the related mechanisms. Moreover, a period of safety time must be set between the carriage-stepping andstop-clearing operations so as to assure safe completion of the respective operations. Still further, in the case where separate drives are utilized in a calculating machine, spring means are usually employed for the backstepping motion of the carriage. Such motion is influenced by the resiliency of the spring means which will be widely variable with temperature and by-the friction between the related machine components, which friction will also be widely varied with thetemperature, lubrication and other fortuitus factors.- With a conventional calculating machine of the mentionedkind,.there fore, it is not possible to obtain'a fully reliable back-stepping motion of the carriage.

It is a general object of the present invention to eliminate or at least minimize the above-mentioned difficulties and shortcomings in the art of calculating machine.

According to the present invention, there is provided a device for the step-by-step motion of a setting carriage of a calculating machine, comprising a two-armed lever member pivotally mounted on a fixed pin secured to a machine frame, one of the arms of said lever member being operatively connected to a rod member which is movable to cyclically operate the device while the other arm has a pin mounted thereon, said rod member being operable to rotate said lever member about said fixed pin, a bell crank having a first arm operatively connected to said pin on said lever member and a second arm extending substantially at right angles with respect to said first arm, said second arm being adapted for engagement with one of stops in the row of zero stops mounted on said setting carriage, and means for allowing said bell crank first to rotate about said fixed pin into engagement at said second arm with one of said stops and then to move substantially linearly for thereby shifting said setting carriage a step when said bell crank is actuated by said pin on said lever member.

In a preferred embodiment of the invention, the above-stated allowing means comprise an elongated slot formed in the bell crank and extending in a direction substantially parallel to that of the stepping motion of thesetting'carriage when the bell crank is in its fully rotated position, and a spring member always biasing the bell crank generally away from the carriage. The springmemberis arranged in such a manner as to be operable to hold the bell crank in engagement with the fixed pin at one end of the elongated slotso that the bell crank, when actuated by the pin on the lever member, is rotated about the fixed pin until the second arm of the bell'crank is brought into engagement with and depresses one of the stops on the carriage. The continued actuation by the pin on the lever member will cause the bell crank to then move substantially linearly as guided by the elongated slot whereby the setting carriage is shifted .a step through the engagement of the second arm of the bell crank with the mentioned one stop.

The above and other objects and features of the present invention will becomeapparent from the following description of a preferred embodiment of the invention with reference to the accompanying drawings.

FIG. 1 is a plan view of a setting carriage shifting device according to an embodiment of the present invention, with the components of the device being shown in their rest positions;

FIG. 2 is'a similar view to FIG. 1 but illustrating the components in positions in which a first stop-clearing operation has been completed; and

FIG. 3 is a similar view to FIGS. 1 and 2 but illustrating the components in positions in which the setting carriage has been shifted back a step from the positio shown in FIG. 2.

Referring to the drawings, the device of the present invention includes a two-armed lever l pivotally mounted on a pin or shaft 2 fixed to a machine frame (not shown). The lever 1 has an arm la engaged with a rod 3 by means of which the machine is cyclically operated. The lever I also has another arm lb extending substantially at right angles with respect to the arm 10 and having a pin 4 secured to the outer end of the arm lb. A bell crank lever 5 is also pivotally mounted on the pin 2 by means of anelongated hole or slot 6 formed in the bell crank lever 5, the slot 6 extending in a direction substantially parallel to that of the stepping motion of the setting carriage to be described later. The bell crank 5 includes'an arm 5a having formed therein a second elongated hole or slot 7 extending in a direction substantially perpendicular to that of the first slot 6. The second slot 7 receives the pin 4 on the arm lb of the lever 1 so that the bell crank 5 is also pivotable about the pin 4. It will be appreciated that the pivoting motion of the bell crank 5 about the pin 2 is limited by the cooperation of the pin 4 and the slot 7 while the pivoting motion of the bell crank 5 about the pin 4 is limited by the cooperation of the pin 2 and the slot 6.

The arm 5a of the bell crank 5 has an outer end or extension 8 which is in slidable engagement with a guide slot 9 formed in a stationary part 10 of the machine frame. A tension spring 11 is connected at one end to the bell crank arm 5a while the other end of the spring is secured to a stationary part 12 of the machine frame. The other arm 5b of the bell crank 5 is kept in engagement with a fixed stop 20 of the machine when the bell crank is in its rest position. The spring 11 is oriented in such a direction that an imaginary inward extension line of the spring intersects the line joining the pins 2 and 4 for. reasons which will become apparent later. The arm b has a lateral extension-13 extending in a direction substantially opposite to that of the arm 5a, the extension 13 having a projection 14 formed at the forward end of the extension. The extension 13 and the projection 14 are adapted to be positioned in opposite relationship to one of stops of the afore-mentioned setting carriage 16 when the latter is in a rest position. The stops 15 may be either in their set positions in which they project out of one side of the carriage 16 or in their cleared positions in which the stops project out of the other side of the carriage.

The carriage 16, which tends to be moved leftwards by a tension spring 18 extending between the carriage and a stationary frame portion, is retained by a dog 17 which engages the leftmost one of stops 15 which project out of the bottom side of the carriage, i.e., the stops 15 which are in their cleared positions.

In operation, the rod 3 which, as previously stated, is associated with the cyclical drive of the calculating machine, is automatically moved in a direction indicated by an arrow A at a given instant of the machine operation. This movement of the rod 3 pivotally rotates the lever 1 about the pin 2 so that the arm lb of the lever l is swung or moved in a clockwise direction, as indicated by an arrow B, together with the pin 4 which is in sliding engagement with the slot 7 in the arm 5a of the bell crank lever 5. The latter, therefore, is caused to rotate about the pin 2 in the same direction. This rotation is possible for the reasons that the pin 2 is fixed to the machine frame and that the spring 11, which extends generally laterally with respect to the bell crank arm 5a, is operable to leftwardly pull the portion of the bell crank 5 which is downward of the connection to the pin 4 so that the rightmost end of the slot 6 in the bell crank is kept in engagement with the pin 2. It will be appreciated that, unless the'spring 11 is operable in such manner, the clockwise movement of the pin 4 will cause the bell crank 5 to move generally rightwardly as guided by the slot 6 rather than rotating about the, pin 2.- As the clockwise rotation of the bell crank lever 5 is continued, the extension 13 and the projection 14 of the bell crank arm 5b are brought into engagement with and depresses the one of the stops 15 of the carriage 16 which one stop is in alignment with the extension 13 at the moment. The position taken by the bell crank 5 at this moment is shown in FIG. 2.

Thus, the mentioned one stop 15 is shifted downwardly into its cleared position in which the stop extends from the bottom side of the carriage 16, as shown in FIG. 2, thus getting into engagement with the dog 17, whereby any further leftward movement of the carriage 16 is prevented. At the same time, the downward movement of the arm 5b, i.e., the clockwise rotation of the bell crank 5, is stopped by the engagement between the forward end of the extension 13 and said one stop 15 while the lever 1 continues its rotation shifted in a direction determined by the engagement of the pin 2 with the slot 6 in the bell crank 5 and also by the engagement of the extension 13 thereof with the lastly cleared stop 15. This motion of the bell crank 5 is allowed by the shape of the slot 6, the major axis of which is now made parallel to the direction in which the carriage 16 is shifted. Thus, the carriage is advanced a step rightwards or backwards through the engagement of the projection 14 on the extension 13 with the left shoulder of the lastly cleared stop 15 on the carriage l6.

The final position taken by the assembly is shown in FIG. 3 in which it will be seen that the slot 6 has been rightward moved with respect to the fixed pin 2 a distance which corresponds .to the distance of a single step of the carriage l6, i.e., a distance from one stop 15 to the next one. It will be appreciated that when the up ward force which has been exerted on the arm in of the lever l by the rod 3 is released, the lever l and the bell crank 5 are automatically returned by the spring 11 to their initial or inoperative positions shown in FIG. 1.

What is claimed is:

l. A device for the step-by-step motion of a setting carriage of a calculating machine, comprising a twoarrned lever member pivotally mounted on a fixed pin secured to a machine frame, one of the arms of said lever member being operatively connected to a rod member which is movable to cyclically operate the device while the other arm has a second pin mounted thereon, said rod member being operable to rotate said lever member about said fixed pin, a bell crank having a first arm, operatively connected to said pin on said lever member and a second arm extending substantially at right angles with respect to said first arm, said second arm being adapted for engagement sequentially with one of a plurality of stops mounted on said setting carriage, and means responsive to rotation of said lever member about said fixed pin for initially rotating said bell crank about said fixed pin so as to bring its said second arm into engagement with one of said stops for depressing said one stop and thereafter moving said bell crank substantially linearly in response to further rotation of said lever member for thereby shifting said setting carriage a step.

2. A device as defined in claim 1 in which said responsive means comprises an elongated slot formed in said bell crank and extending in a direction substantially parallel to that of said stepping motion of said setting carriage when said bell crank is in its fully rotated position, and a spring member always biasing said bell crank generally away from said carriage, said spring member being operable to hold said bell crank in engagement with said fixed pin at one end of said elongated slot in said bell crank so that the latter, when actuated by said pin on said lever member, is rotated about said fixed pin until said second arm of said bell crank is brought into engagement with and depresses one of said stops, the continued actuation by said pin on said lever member causing said bell crank to then move linearly as guided by said elongated slot against said spring member for thereby causing said carriage to be shifted a step through the engagement of said second arm with said one stop.

3. A device as defined in claim 2 in which said spring member is a tension spring having one end secured to a stationary machine frame and the other end connected to the portion of said first arm of said bell crank between said connection to said pin on said lever member and said elongated slot.

4. A device as defined in claim 3 in which said second arm of said bell crank has a lateral projection 5 adapted to be brought into engagement with one of said stops on said carriage when said bell crank is rotated about said fixed pin.

l I l l 

1. A device for the step-by-step motion of a setting carriage of a calculating machine, comprising a two-armed lever member pivotally mounted on a fixed pin secured to a machine frame, one of the arms of said lever member being operatively connected to a rod member which is movable to cyclically operate the device while the other arm has a second pin mounted thereon, said rod member being operable to rotate said lever member about said fixed pin, a bell crank having a first arm operatively connected to said pin on said lever member and a second arm extending substantially at right angles with respect to said first arm, said second arm being adapted for engagement sequentially with one of a plurality of stops mounted on said setting carriage, and means responsive to rotation of said lever member about said fixed pin for initially rotating said bell crank about said fixed pin so as to bring its said second arm into engagement with one of said stops for depressing said one stop and thereafter moving said bell crank substantially linearly in response to further rotation of said lever member for thereby shifting said setting carriage a step.
 2. A device as defined in claim 1 in which said responsive means comprises an elongated slot formed in said bell crank and extending in a direction substantially parallel to that of said stepping motion of said setting carriage when said bell crank is in its fully rotated position, and a spring member always biasing said bell crank generally away from said carriage, said spring member being operable to hold said bell crank in engagement with said fixed pin at one end of said elongated slot in said bell crank so that the latter, when actuated by said pin on said lever member, is rotated about said fixed pin until said second arm of said bell crank is brought into engagement with and depresses one of said stops, the continued actuation by said pin on said lever member causing said bell crank to then move linearly as guided by said elongated slot against said spring member for thereby causing said carriage to be shifted a step through the engagement of said second arm with said one stop.
 3. A device as defined in claim 2 in which said spring member is a tension spring having one end secured to a stationary machine frame and the other end connected to the portion of said first arm of said bell crank between said connection to said pin on said lever member and said elongated slot.
 4. A device as defined in claim 3 in which said second arm of said bell crank has a lateral projection adapted to be brought into engagement with one of said stops on said carriage when said bell crank is rotated about said fixed pin. 